Paper feeder

ABSTRACT

A paper feeder includes a base, a roller adjacent to the base, a holder for holding a paper, and a torsional element. The holder has a pivot end and a movable end, wherein the pivot end is pivoted to the base. The torsional element is disposed at a position where the holder is pivoted to the base, and provides torsion to move the movable end of the holder to be pressed against the roller, such that a front edge of the paper is raised to be in contact with the roller. As the roller rotates, the paper is fed into a paper feed track by a frictional force.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 095218133 filed in Taiwan, R.O.C. onOct. 13, 2006, the entire contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a paper feeder, and more particularlyto a paper feeder that reduces the occupied space and simplifies theassembling procedure.

2. Related Art

Various types of printing and output devices, such as printers,scanners, copiers and multi-functional peripherals (MFPs), are nowavailable in the market. In each of these devices, two rubber rollers,including a pickup roller and a feed roller, are used to pickup and feedpapers. The paper is firstly picked up from a paper tray by the pickuproller, and then is fed by the feed roller to perform the prearrangedtask, and finally is conveyed outside the device. The power for themotion of the two rollers is provided by transmission elements, such asgear sets or a belt.

FIGS. 1 and 2 are side views of paper feeders in the prior art.

FIG. 1 is a side view of a paper feeder in the prior art having a lowerroller. A feed roller 20 is disposed on one side a paper tray 12, and isconnected to a pickup roller 10 with a transmission mechanism 11. Thepickup roller 10 moves downward to the paper tray 12 to be in contactwith a paper 13, such that the pickup roller 10 drives the paper 13 tomove to the feed roller 20 along a tangential direction of the roller. Alower roller 30 is disposed under the feed roller 20, and the lowerroller 30 is in contact with the feed roller 20 appropriately.Therefore, when the paper enters, it is blocked by the lower roller 30,such that the paper 13 is rolled by the feed roller 20 to pass throughthe two rollers.

FIG. 2 is a side view of a paper feeder in the prior art having a lowerfriction plate mechanism. Here, the lower roller 30 is replaced by alower friction plate mechanism 40. The lower friction plate mechanism 40includes a lower friction plate 41 in contact with the feed roller 20appropriately, and an elastic mechanism 42 combined to a bottom surface43 of the lower friction plate 41, so as to provide an elastic forceperpendicular to a tangential direction of rolling.

The two types of paper feeders described above are disadvantageous interms of the design cost and the lifetime. Therefore, Taiwan Patent No.500,061 entitled “Paper Separation Device for Automatic Paper Feeding”filed on Aug. 21, 2002 adds an elastic element on one side of thefriction plate, so as to provide an elastic force opposite to thetangential direction of the feed roller, such that the friction platemoves along a direction opposite to the tangential direction. Thus, thelifetime of the friction plate is increased, and the cost is reduced.

According to the solutions provided in the prior art or Taiwan PatentNo. 500,061, a roller set including two or more rollers is required, ora friction plate mechanism has to be added to pickup, feed, and separatepapers. Therefore, the shortcomings of the mechanism include thecomponents are too complicated to assemble difficulty, and thecomponents occupy too much space, to cause the mechanism is not lightand thin enough. In addition, the elastic element described in TaiwanPatent No. 500,061 must provide an opposite elastic force according tothe acting force of the feed roller. As the elastic element outputs theforce linearly, the force output is influenced by the compressionamount, while the compression force is easily influenced by thetolerance in assembling. Therefore, the design problem that the elasticforce output is difficult to control will occur.

Furthermore, U.S. Pat. No. 6,499,736 entitled “Paper Feeder for Paperswith Different Thickness” filed on Dec. 31, 2002 disclosed that a rollerdevice is used to perform the pickup motion, and a torsional springsliding in a sliding slot is used to provide driving forces to pick uppapers with different thickness.

Though U.S. Pat. No. 6,499,736 simplifies the roller set to a singleroller, but the torsional spring is similar to the elastic element ofTaiwan Patent No. 500, 061, the torsional spring is still disposed underthe roller. Though the assembling procedure is simplified slightly, butthe space that the assembled device occupies is not reduced, which doesnot satisfy the market requirements of being slight, thin, and simple indesign, and is not helpful to improve the competitiveness andconvenience of the product.

SUMMARY OF THE INVENTION

In the prior art, a roller set comprising a plurality of rollers isrequired to pickup and feed papers, and an elastic element providing theelastic force is disposed under the roller set. Therefore, theassembling is complicated, and the assembled components occupy too muchspace.

In view of the above problems, the present invention provides a paperfeeder, which eliminates the limitations or disadvantages in the priorart that the components are too complicated and difficult to assemble,and that the assembled components occupy too much space.

The present invention relates to a paper feeder, which comprises a base,a roller, a holder, and a torsional element. The roller is disposedadjacent to the base. The holder has a pivot end and a movable end, andis used to hold at least a paper, wherein the pivot end is pivoted tothe base. The torsional element is disposed at a position where theholder is pivoted to the base, and provides torsion to move the movableend of the holder to be pressed against the roller, such that a frontedge of the paper is raised to be in contact with the roller. As theroller rotates, the paper is fed into a paper feed track by a frictionalforce.

The effect of the present invention is simplifying the assemblingprocedure of the paper feeder, reducing the required space, andimproving the lifetime.

The paper feeder only comprises a base, a roller, a holder, and atorsional element only, so the complexity in assembling and the time forassembling is reduced significantly. Moreover, as the torsion output ofthe torsional element does not change much, even if the assemblytolerance occurs in the assembling, the torsion output of the torsionalelement is still controllable. Thus, the stability of picking up andfeeding the paper for the paper feeder is improved.

Furthermore, an accommodation portion is recessed on the base toaccommodate the holder and the torsional element, and the accommodationspace of the accommodation portion allows the holder to swing inside butnot to be exposed outside the accommodation portion. Thus, the volume ofthe assembled paper feeder is reduced significantly, which satisfies therequirements of being light and simple in the design.

In addition, the holder is fabricated with a plastic flat plate. Thus,the material cost of the holder is reduced, and the weight is low.Moreover, the movable end of the holder is covered by a metal sheet, sothe frictional force between the roller and the holder is reduced whenthere is no paper, which prevents additional abrasion loss of theroller, and increases the lifetime of the roller. When the roller picksup and feeds the paper, the frictional force between the paper and theholder is also reduced, such that the roller drives the paper smoothly.

Detailed features and advantages of the present invention are describedin the embodiments below, and their content is adequate for thoseskilled in the art to understand the technical content of the presentinvention and to implement the present invention. According to thecontent disclosed in the specification, the claims, and the drawings,those skilled in the art can easily understand the objects andadvantages of the present invention.

The description on the content of the present invention above and thedescription on the embodiments below are used to exemplify and explainthe principle of the present invention, and provide further explanationon the claims of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given herein below for illustration only, and thusare not limitative of the present invention, and wherein:

FIG. 1 is a side view of a paper feeder in the prior art having a lowerroller;

FIG. 2 is a side view of a paper feeder in the prior art having a lowerfriction plate mechanism;

FIG. 3 is a sectional side view of the present invention;

FIG. 4 is a schematic stereogram of the present invention; and

FIG. 5 is a partially enlarged schematic view of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

To make the object, structure, features and function of the presentinvention more understandable, the present invention is illustratedbelow in detail with reference to the embodiments.

The paper feeder according to the disclosure of the present invention isapplicable to devices with paper pickup and feed functions, such asfaxes, printers, copiers, multi-functional peripherals (MFP), orscanners. In the detailed illustration of the present invention below,an MFP is used as a preferred embodiment of the present invention.However, the accompanying drawings are for reference and illustrationonly, but not intended to limit the present invention.

Referring to FIG. 3, a paper feeder 100 according to an embodiment ofthe present invention includes a base 110, a roller 120, a holder 130,and a torsional element 140.

The base 110 is disposed at an inlet of a paper feed track of the MFP.The roller 120 is disposed adjacent to the base 110, and is used todrive a paper with a frictional force, so as to pickup and feed thepaper at the inlet of the paper feed track, such that the paper entersthe paper feed track. The holder 130 for holding the paper is a flatplate of plastic material. The width of the plate is to the same as thatof the paper, or is less than that of the paper. The holder 130 has apivot end 131 and a movable end 132. The pivot end 131 is pivoted to thebase 110, such that the holder 130 rotates relative to the base 110. Themovable end 132 may be pressed against the roller 120 or move away fromthe roller 120 with the rotation of the holder 130. The torsionalelement 140 is disposed at a position where the holder 130 is pivoted tothe base 110, so as to provide a torsion, such that the holder 130 is atan angle to the base 110, and the movable end 132 moves to be pressedagainst the roller 120. When the torsion angle of the torsional element140 does not change much, the change in the torsion output of thetorsional element 140 is also reduced. Even if a slight tolerance occursduring assembling, the tolerance has less influence on the torsion angleas compared to the influence on the compression amount of a linearelastic element such as a linear spring. Therefore, in the presentinvention, even if the assembly tolerance exists, the torsion output ofthe torsional element 140 is still controlled within a certain range,which improves the stability of picking up the paper for the paperfeeder 100.

The holder 130 holding the paper raises the front edge of the paper witha forward force provided by the torsional element 140, such that thefront edge of the paper is in contact with the roller 120. Moreover, asthe torsion output of the torsional element 140 is not easily influencedby the assembly tolerance, the forward force for the movable end 132 ofthe holder 139 pressing against the roller 120 may be controlled at anappropriate value, such that an adequate frictional force exists betweenthe roller 120 and the paper to drive the paper to move forward.Meanwhile, the forward force is not excessively great, and will notcause an over great frictional force between the paper and the holder,which prevents the crinkle or breakage of the paper.

As shown in FIG. 3 and FIG. 4, an accommodation portion 111 is recessedon the base 110. The accommodation space is used to accommodate theholder 130 and the torsional element 140, and the accommodation space ofthe accommodation portion 111 allows the holder 130 to swing inside butnot to be exposed outside the accommodation portion 111. Therefore,after the base 110 is pivoted with the holder 130 and the torsionalelement 140, the height is not increased. Thus, the volume of theassembled paper feeder 100 is reduced. Moreover, the movable end 132 ofthe holder 130 is covered by a metal sheet 133 with a low frictionalcoefficient. When no paper is held, the metal sheet 133 lowers thefrictional force between the roller 120 and the holder 130, so as toreduce the abrasion loss of the roller 120, and to improve the lifetimeof the roller 120. Meanwhile, when the roller 120 picks up and feeds thepaper, the metal sheet 133 reduces the frictional force between thepaper and the movable end 132 of the holder 130, such that the roller120 drives the paper smoothly, and does not cause the abrasion orcrinkle of the paper.

Referring to FIG. 5, a pivot base 112 is disposed on one side of theaccommodation portion 111. The pivot base 112 has two opposite pivotholes 113, and the pivot end 131 of the holder 130 has two coaxial pivotshafts 134 extending towards opposite directions and inserted into thetwo pivot holes 113 respectively. Thus, the pivot end 131 of the holder130 is completely jointed with the pivot base 112 of the accommodationportion 111. The torsional element 140 is disposed in the pivot shafts134 of the holder 130, with an end of the torsional element 140 beingconnected to the holder 130, and the other end being connected to thepivot base 112, so as to provide a torsion to the holder 130.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A paper feeder, for picking up and feeding at least a paper,comprising: a base; a roller, adjacent to said base; a holder, pivotedto said base, for holding the paper; and a torsional element, disposedat a position where said holder is pivoted to said base, for providing atorsion such that a movable end of said holder moves to be pressedagainst said roller.
 2. The paper feeder as claimed in claim 1, whereinan accommodation portion is recessed on said base, so as to accommodatesaid holder and said torsional element.
 3. The paper feeder as claimedin claim 2, wherein a pivot base is disposed on one side of theaccommodation portion, and a pivot end of said holder is pivoted to thepivot base.
 4. The paper feeder as claimed in claim 3, wherein the pivotbase has two pivot holes, and the pivot end has two coaxial pivot shaftsextending towards opposite directions and inserted into the two pivotholes respectively.
 5. The paper feeder as claimed in claim 1, whereinthe material of said holder is plastic.
 6. The paper feeder as claimedin claim 1, wherein said holder is a flat plate.
 7. The paper feeder asclaimed in claim 1, wherein the movable end of said holder is covered bya metal sheet.